Not every artist gets involved in politics in their songs, but there are a lot that do. I particularly like the way Orphaned Land, a Palestinian metal band, try to bridge that seemingly insurmountable gap between the two old enemies through the medium of music.
"All is One" - Orphaned LandNote: it should go without saying that if you post a political video you don't have to subscribe to the beliefs in it. It is, after all, as someone once wrote, only rock and roll.
The undisputed classic - Scott Beach's "Religion and Politics" (1976). A regular on The Doctor Demento Show for decades.
One of ex-Marillion singer/frontman Fish's better and more political tracks.
"The Pilgrim's Address" - Fish (Fellini Days)
Several good ones to choose from by these guys but I'll go with this one right now...
The Clash - Washington Bullets